Zimbabwean President Robert Mugabe has challenged a TV interviewer when quizzed about any retirement plans, asking him: "Do you want me to punch you to the floor to realise I am still there?"

The 92-year-old, known for his pugnacious comments, was responding to an interviewer from state TV after a question about who would succeed him.

"Why 'successor' when I am still there?" he said in the interview. "Why do you want a successor?"

Mr Mugabe, who has led Zimbabwe since the country was formed in 1980 from the ashes of white-ruled Rhodesia, said he has no plans to hand over power and ruled out grooming his politically ambitious wife Grace as his chosen successor.

"Grooming a successor, is it an inheritance?" Mr Mugabe asked. "In a democratic party you don't want leaders appointed that way. They have to be appointed properly by the people. Succession is not part of our culture."

He turned 92 on February 21 amid fierce squabbling in the ruling Zanu-PF party in anticipation of his succession.

He defended his wife's entry into politics and criticised people for badmouthing her.

On Thursday, Zanu-PF spokesman Simon Khaya Moyo announced the suspension from the party of cabinet minister Chris Mutsvangwa and several other officials on allegations of disrespecting the first lady.